Re: [libvirt] [PATCH v2 5/7] conf: Introduce new <hostdev> attribute 'display'

On 07/09/2018 06:24 PM, Erik Skultety wrote: > QEMU 2.12 introduced a new type of display for mediated devices using > vfio-pci backend which allows a mediated device to be used as a VGA > compatible device as an alternative to an emulated video device. QEMU > exposes this feature via a vfio device property 'display' with supported > values 'on/off/auto' (default is 'off'). > > This patch adds the necessary bits to domain config handling in order to > expose this feature. Since there's no convenient way for libvirt to come > up with usable defaults for the display setting, simply because libvirt > is not able to figure out which of the display implementations - dma-buf > which requires OpenGL support vs vfio regions which doesn't need OpenGL > (works with OpenGL enabled too) - the underlying mdev uses. > > Signed-off-by: Erik Skultety <eskultet(a)redhat.com&gt; > ---

> +static int > +qemuDomainHostdevDefPostParse(const virDomainHostdevDef *hostdev, > + const virDomainDef *def) > +{ > + const virDomainHostdevSubsysMediatedDev *mdevsrc; > + > + if (hostdev->mode == VIR_DOMAIN_HOSTDEV_MODE_SUBSYS) { > + switch ((virDomainHostdevSubsysType) hostdev->source.subsys.type) { > + case VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_USB: > + case VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_PCI: > + case VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_SCSI: > + case VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_SCSI_HOST: > + break; > + case VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_MDEV: > + mdevsrc = &hostdev->source.subsys.u.mdev; > + return qemuDomainHostdevMdevDefPostParse(mdevsrc, def); > + case VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_LAST: > + default: > + virReportEnumRangeError(virDomainHostdevSubsysType, > + hostdev->source.subsys.type); > + return -1; > + } > + } > + > + return 0; > +} > + Again, these two ^^ are validate callbacks not PostParse. You are not filling in missing information, you are checking (=validating) whether user provided XML is valid.